text: Laboratory-scale nitric acid syntheses abound.  Most take inspiration from the industrial techniques.   
  A wide variety of nitrate salts metathesize with sulfuric acid () &mdash; for example, sodium nitrate:
  Distillation at nitric acid's 83 °C boiling point then separates the solid metal salt residue.  The resulting acid solution is the 68.5 % azeotrope, and can be further concentrated (as in industry) with either sulfuric acid or magnesium nitrate.  
  Alternatively, thermal decomposition of copper(II) nitrate gives nitrogen dioxide and oxygen gases; these are then passed through water or hydrogen peroxide as in the Ostwald process:
  :or